Electronic air cleaning cell

ABSTRACT

An electronic air cleaner having a series of alternate groups of parallel collecting plates, each group having spaced aligned predrawn holes and clearance holes and sections of metal tubes of equal length expanded and locked in precise position in the aligned drawn holes of each group and passing through the clearance holes of another group of collecting plates. The metal tubes are rigidly held between spaced parallel panels to equally space the groups of collecting plates therebetween and a means to maintain lateral alignment of the metal tubes is provided to maintain the alternate groups of collecting plates in position and equally spaced in parallel relation to each other. The metal tubes are preferably expanded to a nonround shape such as rifled or polysided to enhance engagement with the plates. The preferred end panel is conductive with spaced cutouts having overlying insulating plates with at least one tube aligning hole. The plate is loosely attached to the end panel to permit alignment of the holes with selected conductor tubes. Depressions are also provided in the panel for other selected tubes to permit engagement of the tube ends with the end panels in the same plane.

United States Patent [72] Inventors Paul Aitkenhead Ross Township,Allegheny County; Robert Ruhlman, Pittsburgh; Lewis G. McClintock,Pittsburgh, all of. Pa. [21] Appl. No. 889,142 [22] Filed Dec. 30, 1969[45] Patented June 1, 1971 [73] Assignee Electro-Air Division, EmersonElectric Company Continuation-impart of application Ser. No. 530,993,Mar. 1, 1966, now abandoned.

[54] ELECTRONIC AIR CLEANING CELL 18 Claims, 19 Drawing Figs.

[52] US. Cl 55/138, 55/139, 55/143, 55/145, 55/146, 55/151, 55/154 [51]Int. Cl B03c 3/00 [50] Field ofSearch 55/138, 139,143,145,146,151,154,137, 136

[56] References Cited UNITED STATES PATENTS 2,696,893 12/1954 Richardson55/145X 2,873,000 2/1959 Elam 55/138 2,900,042 8/1959 Coolidge, Jr. eta1. 55/143X 2,932,359 4/1960 Fields 55/143X 3,006,066 10/1961 Grossen eta1. 55/146X 3,124,439 3/1964 Rittenhouse 55/143 3,175,341 3/1965 Winter55/143 FOREIGN PATENTS 155,913 3/1954 Australia 1. 55/145 668,698 3/1952Great Britain 55/138 Primary Examiner Dennis E. Talbert, Jr.Altorney--Carothers and Carothers ABSTRACT: An electronic air cleanerhaving a series of alternate groups of parallel collecting plates, eachgroup having spaced aligned predrawn holes and clearance holes andsections of metal tubes of equal length expanded and locked in preciseposition in the aligned drawn holes of each group and passing throughthe clearance holes of another group of collecting plates. The metaltubes are rigidly held between spaced parallel panels to equally spacethe groups of collecting plates therebetween and a means to maintainlateral alignment of the metal tubes is provided to maintain thealternate groups of collecting plates in position and equally spaced inparallel relation to each other.

The metal tubes are preferably expanded to a nonround shape such asrifled or polysided to enhance engagement with the plates.

The preferred end panel is conductive with spaced cutouts havingoverlying insulating plates with at least one tube aligning hole. Theplate is loosely attached to the end panel to permit alignment of theholes with selected conductor tubes. Depressions are also provided inthe panel for other selected tubes to permit engagement of the tube endswith the end panels in the same plane.

PATENTEU JUN 1:971 581,470

SHEET 2 BF PATENTED JUN 1 I97! SHEET 5 OF 7 50 x 5 m mu-m H m mm m g 4 0W? m r c r a. a A w Law 5 s m PATEN'I'TIMUN H971 3,581,470

' SHEET 7 OF 7 /5- I -54 3 ZZZ /NVENTOR5 PAUL W. AITKENHAD Roster Pam.MAN LEW/.5 6. Mc Cuurucx Y (A 201M625 (Axon/ms file/e A rraew Y5ELECTRONIC AER CLEANHNG ClElLlL CROSS REFERENCE This application is acontinuation-in-part of application Ser. No. 530,993, filed Mar. 1,1966, now abandoned, for Method and Apparatus for Manufacturing AirCleaner Cells.

SUMMARY OF lNVENTlON This invention-relates generally to electronic aircleaners and more particularly to an improved collecting cell.

Electronic-collecting cells usually consist of a series of spacedelectrodes insulatingly supporting therebetween an alternate series ofpositive ionizing wires in front of an alternate series of positivelyand negatively charged collecting plates which attract the ionizedparticles of dirt carried therethrough by forced air flow.

it is a serious problem to construct these collecting cells economicallyand at the same time to make them efficient and uniform in theirproduction.

The principal object of this invention is the provision of a new andimproved collecting cell permitting uniform, new and novel productiontechnique to carry out the making of some parts and assembly of the sameand to provide a collecting cell which is economical to construct yethas great longevity and dependability.

The electronic air-cleaning collector cell of the present inventionconsists of a series of alternate parallel collecting plates providingplate groups of different polarity. The plates are provided with aplurality of aligned mounting holes and clearance holes in each group ofcollecting plates'with conductor tubes positioned in the mounting holesto support their respective group of collecting plates of one polarityand passing through the clearance holes of alternate groups ofcollecting plates of different polarity. Parallel end panels areprovided with holes matching the location of the bores of the conductortubes, but the holes are smaller than the outside diameters of theconductor tubes. The conductor tubes are aligned with their respectiveend panel holes and secured such that the tube ends about the insidefaces of the end panels. Thus when the end panels are thus secured ordrawn in towards each other to engage all conductor tube ends, thealternate groups of collecting plates will automatically be aligned andplaced in equally spaced parallel relation with each other in theelectronic air-cleaning cell. lnsulating means are provided on the endpanels to insulate the conductor tubes of different polarity.

Thus, assuming that the opposed inside surfaces of the end panels whichengage the tube ends are each respectively equally spaced, then eachconductor tube is of equal length. Thus, before the end panels areapplied to the collecting cell unit, the spacing between the adjacentcollector plates may be gauged and the tubes then simultaneously cut toequal length. When the cell is inserted between the end panels and theend panels are brought together against the ends of the tubes and theresecured, the correct spacing will automatically be assumed andmaintained.

Bolt means may be extended through the end panels and selected of theconductor tubes to clamp the end panels against the conductor tubes.

The mounting holes in the collector plates which receive and tightlyengage the conductor tubes, are preferably predrawn to provide afrustoconical opening that does not have a cylindrical surface butalways changes along the cone. The drawn holes are punched to provide asmaller opening drawn into a hell with a frustoconical section that hasa steep angle to provide greater surface engagement on the tube than themere thickness of the material of the plate. This drawn frustoconicalhole is thus tightly seized and clamped when the tube is expandedtherein without deflecting the surface planes of the plates. This is dueto the fact that the outer portion of the frustoconical drawn sectionengages the tube whereas the bell-shaped portion of the drawn hole isfree of the tube. When the tube is expanded it does not engage withinthe parallel planes of the plate and thus does not misshape the same.

The expanded conductor tubes are preferably expanded to a nonround outersurface thereby providing a novel and much more secure interlock withtheir respectively reshaped collec tor plate mounting holes thusproviding assured engagement and spacing. The conductor tubes may beexpanded to their nonround shape to engage the predrawn holes by riflingthe tube here with a rifling expansion mandrel or by expanding it to apolysided configuration. Thus engagement with the conductor plates isenhanced over the structure which is constructed by drawing a roundedmandrel through the conductor tubes to expand the same.

Furthermore, the drawing of a rounded mandrel through the conductor tubebores causes the tubes to stray or bend laterally from their axialposition away from each other thereby distorting the flat conductorplates. This takes place particularly adjacent the ends of the cell. Therifling expanded conductor tubes of the collector cell of the presentinvention provide a collecting cell unit which has no distorted platesas the expansion by rifling prevents lateral wandering or bending of thetubes.

Each tube is abutted against the spaced parallel end panels of the celland selected of them are secured by headed coaxial rods in the tubeswith a speed nut. The top and bottom of these insulating plates aresecured together by flanged metal angular sections to support theionizing frame at the front of the cell, an optional large mesh screenat the front and the removable screen at the back ,to catch the largegobs of dirt that are apt to be blown from the plates after beingpermitted to accumulate too long a period of time.

The collecting cell unit is also provided with a unitary ionizer groundplate having upper and lower parallel bars with rearwardly struckuniformly spaced parallel ionizing electrodes. Spaced insulators areprovided on each bar carrying opposed bus rods above and below theionizing electrodes with ionizing wires suspended between the bus rodsand substantially centered between the ionizing electrodes. Opposed topand bottom panels are provided having intumed marginal side flangeswhich extend beyond the sides of the end panels to form opposed troughson the up and down stream sides of the cell to receive mechanical filterscreens and add to the rigidity of the cell striicture. These top andbottom panels are secured at their ends to their end panels. Tofacilitate this, the end panels are provided with end flanges.

The end panels are preferably and novelly metal panel members providedwith spaced cutouts. Insulating plates overlay selected of these cutoutsand are provided with at least one aligning hole. The insulating platessecured loosely to the end panel members to permit alignment of theholes with selected collecting plate conductor tubes. Depressions areprovided in the same panel members for other selected collecting plateconductor tubes in order to place the face of the bottom wall of suchdepressions which will contact a tube end in the same plane as theinsulating panel faces which will also engage tube ends therebycompensating for the depth of the cutouts. This structure provides amuch more economical end panel with ease of manufacture.

Those conductor tubes not having a bolt passing therethrough may bealigned and secured relative to their respective end panel holes bytapered cylindricabshaped loclt lugs which may be forced into thealignment holes in the end panels and on into the bore of the tubes.Such lock lugs are provided with flanges which engage the inside surfaceof the end panels upon insertion thereby preventing dislodgment.

Conductor straps may be provided on the outside of a selected insulatingplate and connected to selected of the conductor tubes to permit lateralelectrical cell connection to an energy source.

Other objects and advantages appear hereinafter in the followingdescription and claims.

The accompanying drawings show, for the purpose of exemplificationwithout limiting the invention or the claims thereto,

certain practical embodiments illustrating the principles of thisinvention wherein.

FIG. l is an enlarged perspective view of a portion of pairs of metalcollecting plates showing clearance holes and predrawn holes secured totubes and fastened to an insulating panel.

FIG. 2 is an enlarged sectional view through a pair of collecting metalplates showing the drawn hole and the expanding mandrel.

FIG. 3 is a perspective view of an open stacking jig with a platefeeding tray showing the cell elevator in its raised position.

FIG. 4 is a perspective view of two E-shaped jig members with a spacertherebetween.

FIG. 5 is a perspective view of the open stacking jig with theplate-feeding tray forward and a portion of the plates stacked in thejig.

FIG. 6 is a perspective view looking over the plate feeding tray on topof the open stacking jig.

FIG. 7 is a perspective view of the closing of the stacking jigillustrating the relative position of the top spacers about to enter thespacers supporting the plates in the jig.

FIG. 8 is a perspective view of the closed stacking jig with the tubespartially inserted in their respective aligned predrawn holes.

FIG. 9 is a perspective view of the act of expanding the tubes in thepredrawn holes of the plates locked in the jig.

FIG. 10 is a perspective view of the open jig with the elevators havingraised the interleaved plates free of the jig spacers.

FIG. 11 is a perspective view of a jig to properly space the interleavedplates from each other on a carriage to prealign the tubes.

FIG. 12 is a perspective view of moving the interleaved and jigged heldplates through dual saws to make the tubes gauging points.

FIG. 13 is an enlarged perspective view of a portion of a completed cellwith parts broken away.

FIG. 14 is a diagrammatic plan view of the punching and stackingapparatus.

FIG. 15 is a circuit diagram for energizing the electronic air cleaningcell of this invention.

FIG. 16 is a circuit diagram for energizing a three phase electronic aircleaner cell of this invention.

FIG. 17 is an enlarged view partly in section showing a conductor tubewith a spiral bore of predetermined configuration abutting an insulatingend panel with a spring locking lug holding the same in position.

FIG. I8 is a front elcvational view in section with portions broken awayshowing an electronic air cleaning collector cell with the collectorplates supported by conductor tubes and having metal end panels withinsulated inserts. The vertical front section is taken along line 18-18of FIG. 19 for the upper two thirds of the figure.

FIG. 19 is a view in side elevation of the metal end panel of the cellshown in FIG. 18.

Referring to FIGS. 1 and 2 of the drawings the energized or positivelycharged plates 1 are spaced from the grounded or negatively chargedplates 2 by the interlocking between each of the respective plates andtheir corresponding tubes. The tubes 3 are secured to the positiveplates 1 and the tubes 4 are secured to the negative plates 2. This ismore clearly demonstrated in the enlarged view of FIG. 2 wherein theplate, regardless of which plate it might be, is provided with a drawnhole 5 which consists in a bell end 6 and a frustoconical end 7, whichbefore the tube is expanded in the predrawn hole having a frustoconicalsection 7, is truly a frustoconical section preferably without anycylindrical sections along the bore thereof. It should be noted that thepredrawn hole of frustoconical section including the bell 6 iscompletely offset or beyond the parallel planes 8 and 10 which definethe opposite sides of a plate.

The tubes 3 and 4 before being inserted into the predrawn holes 5 has athree-eighths or 0.1875 of an inch outside diameter. The inner diameterof the tubes 3 and 4 are approximately 0.305 which is slightly less thanfive-sixteenths which is 0.3125 of an inch. Thus the tubes will readilymove into the bell 6 and through the drawn opening 5 of a stackedsection of plates without much resistance and when the mandrel II withits head 12 is drawn therethrough it is gauged to increase the size ofthe tube approximately 1/64 or 0.1 1312 of an inch which is sufficientfor the expanded tube to grasp a substantial portion of the bellpredrawn hole 5 and lock it firmly in position providing a goodmechanical connection as well as a good electrical connection.

As shown in FIG. I for every series of drawn holes 5 there is acorresponding clearance hole 13 as each of the tubes 3 and 4 arepreferably adjacent each other and parallel. Although the end of thefrustoconical portion of the drawn hole 5 may extend approximatelyhalfway between adjacent plates, the clearance hole 13 is of sufficientsize to provide substantially the same distance between the end of thefrustoconical portion of the drawn hole 5 and the actual tube surfacepassing through the clearance hole 13 as shown in FIG. 2.

The mandrel II has a head 12 which is provided with an initial taperedsection and a trailing tapered section with an intermediate cylindricalgauging section 14. This section I4 is longer than either the taperedsections fore and aft beginning at a diameter equivalent to that of theinner diameter of the tube. Of course, the stem of the mandrel is muchsmaller than the inner diameter of the tube but the important initialtapered section only becomes effective when its diameter reaches theinner diameter of the tube. Different other modes of expanding the tubesmay be practiced. One that is very old in the art is the use of a ballwith a hydraulic fluid. However, in this application there are 10 tubesin all and they may be expanded at the same time by employing themandrel 11 each provided with an expanding head 12.

A jig is shown in FIG. 3 for receiving each of the plates hav ing beenpunched with a required alternate series of drawn holes 5 and clearanceholes 13. The jig, generally speaking, is provided with a stand 15,which supports a table 16 that carries a back gauge plate 17 and a frontplate 18 and a rear plate 20. These plate members are secured togetherto the table and are preferably made of heavy stock for long wear andfor enabling a tight clamping arrangement of the inserted plates of thecell.

As shown in FIG. 3 a hoist or lifting cylinder 21 is shown underneaththe table surface 16 and provided with a piston rod 22 that operates thecrosshead 23 carrying at least four guide members 24 that are connectedtogether at the crosshead 23 and also at the elevator platform sections25 and 26. As shown in FIG. 3 these elevator platform sections areraised above the jig which is shown fully extended for the purpose oflifting the cell out of the jig which is illustrated in FIG. 10. Whereinthe cell 27 is supported by the elevators 2S and 26 above the whole ofthe jig.

In the open jig shown in FIG. 3 there are illustrated sets of spacermembers 28, one row at the back of the jig indicated at 30, one row atthe center of the jig as indicated at 31 and one row at the front of thejig as indicatedat 32. These E-shaped members 28 have their upper endscut at a slant as illustrated at 33 in FIG. 4 and when stacked in thejig are bolted together along their lower end by means of bolts passingthrough appropriate holes to tightly clamp them together and to thefront and rear plates I8 and 20. A spacer plate 34 is positioned betweenthe horizontal common connecting bar of the E that has the upwardlyprojecting fingers forming the E-shaped spacers 28. Thus the bottom ofthe E-shaped spacers 28 are separated by a spacer 34 that may be thesame gauge as the plates 1 and 2 or may be slightly heavier gauging thanthese plates depending upon the capability of tightly clamping theseplates in position. Each of the plates are uniformly stamped andalternately stacked as indicated at 35, as a positive and negative platebut they are preferably gauged so as to have the same total width andlength and when each plate is independently inserted between the groovemade by the sloping faces 33 of the E-shaped member they are shoved tothe bottom or the surface of the spacer 34 as the gauge surface and atthe same time against the rear gauge plate 17. Thus the bottom spacers34 and the rear gauge plate 17 function to square each of the platesinserted in the jig. This automatically aligns the dual sets of holesand when the plates 1 and 2 are alternately positioned progressively inthis jig each of the proper drawn holes 5 will be aligned and thealternate plates with their clearance holes 13 also will be properlyaligned.

As previously stated when the plates are inserted in the jig, the bell 6of the drawn holes 5 all face the same direction which would be towardthe front plate 18 since this is the end that the mandrels 11 with theirheads 12 are inserted.

As shown in FIG. 3 a stack 35 of alternate plates 1 and 2 is placed onthe movable tray 36 and sloped slightly to the back of the stack. Thesepunched plates are readily inserted in the jig but first the elevatorplatforms 25 and 26 must be lowered to a position below the gaugedspacers 34. It may be desirable to use the elevator surfaces 25 and 26as the gauge surfaces in which case the elevator is provided withadjustable stops so that the top surface of the members 25 and 26function as the gauge for the insertion of the plates which may beslightly above the surface of the spacers 34 or halfway up the jig.

Referring now to FIG. 5 the elevator has been depressed to lower thesurfaces 25 and 26 so as to admit the alternate plates 1 and 2 of thestack 35 down in between the adjacent E- shaped spacers in the threerows 30, 31 and 32. As shown in FIG. 5 the plates have been inserted forsubstantially half of the jig and as illustrated these plates extendonly halfway down the jig because the plates shown at 37 are not as deepas the jig. As shown in FIG. 5 the cell has not be completed andadditional plates will be inserted from the tray 36 to finish this cell.It will also be noted that the exposed end of the plates protrude fromthe ends of the E-shaped spacers showing a space indicated at 38.

The tray 36 is mounted on the carriage 40 which is supported by thewheels 41 and joumaled on the stationary frame member 42. Thus the frame42 may extend the carriage tray 36 forwardly out over the jig tosubstantially the front wall 18.

As shown in FIG. 6 the back of the tray 36 is provided with a slopingpush plate 43 which in turn is mounted on the end of a rod 44 thatpasses through the backplate 45 of the tray 36 and extends rearwardly tothe crosshead member 46. A coil spring 47 encircles the rod 44. A cable48 is secured at one end indicated at 50 to the crosshead 46 and has itsfirst pass on the pulley 51 supported from the mounting plate on therear of the backplate 45 and thence on its next pass to the pulley 52pivotally supported from the crosshead 46 and the next pass travels tothe third pulley 53 on the mounting plate on the rear of the backplate45 and thence rearwardly to where it is fastened at 54 to a stationaryframe of the machine. A motor 60 is mounted on the frame 15 and isprovided with a rotary electrical clutch mechanism indicated at 56supplied by current through spaced collector rings and brushes. Themotor 60 may continuously rotate the sprocket 57 and when the clutch 56is energized, the clutch 56 will chuck the threaded rod 49 to feed thetray 36 forward as the tray is fed forward by the threaded rod 49secured to the carriage frame 40 at 55. Thus, the clutch 56 is providedwith threaded arcuate clamp members for threaded engagement with thethreaded rod. The clutch 56 is driven by the gear 57 operated by thechain 58 which in turn is driven from the sprocket 59 of the motor 60.

The rotary clamping chuck 56 is provided with a pair of slip rings 61and 62 which when energized through the brushes 63 and 64 will actuatethe chuck to clamp on the threaded rod to function as a pushrod to feedthe carriage 40 forwardly. As the carriage 40 moves forwardly the tray36 at its other end moves out over the jig due to the cable 48 slidingthe rod 44 forward through the backplate 45 and at the same time theplate 43 moves the stack 35 forwardly on the tray at a predeterminedrate to properly present each of the plates on the front of the stacktray for insertion in the jig. At the same time the spring 47 becomescompressed because of the cable 48 secured at 54 to the frame 15 at oneend and to the crosshead 46 at its other end. When the clutch 56 isreleased. the spring 47 returns the carriage 40 and the plate 43 totheir rearmost positions on the support by the spaced rollers 41 mountedon stationary rails at the rear of the machine frame 15.

When thejig has been completely filled with the number of plates thatare necessary as illustrated in FIG. 7 the jig is ready for closing asclearly shown in this figure as well as in FIGS. 5 to 10. The lead ortop 65 is hinged at 66 to the rear gauge plate 17 which is beefed up byadditional members and is also provided with a tower 69, shown in FIG.6, for supporting a counterweight with a line to the front of the top 65as illustrated at 67 and as secured by the plate 68 to the top 65 asshown in FIG. 8. The line 67 passes upwardly over a pulley adjacent thetop of the tower and thence to a weight which counterbalances the actualweight of the jig top when supported on hinge 66. The top member is madein the form ofa frame having three transverse members 70 which aresecured at their hinged end to the hinged plate 71 and at the front andto the pillow plate 72 which in turn is provided with a block 73 havinga vertical opening to receive the eye of the member 74 and a pin 75which passes through the block and the eye of the member 74. When thehead is locked downwardly, the cylinder 76 is energized to pull thepiston 77 downwardly and thus tightly force the jig top member 65 inposition as shown in FIG. 8.

When it is desired to open the jig the cylinder 76 is energized in theopposite direction to raise the same and when partially raised thelocking pin 75 is withdrawn and the top 65 may be raised to its verticalposition as shown in most of the figures such as FIGS. 5 and 10 givingfree access to the upwardly open jig. As shown in FIGS. 3 and 5 threebars 70 are provided with plates 78 which support a stack of spacingbars 80 and interleaved therebetween a steel spacer plate 81 forinsertion which also engages the sloping faces 33 of the spacers 28while the spacer members 80 interlock with the sloping faces 33 toinsure proper adjustment of the plates in the jig and to retain themagainst any movement during the drawing operation. To allow fordiscrepancy the spacers 80 and their counter plate spacers 81 are boltedtogether in each row and they are suspended on springs to allow thewhole assembly to move back and forth so that they will seek their ownproper position with the lower half of the jig spacer members and thusbecome properly interlocked to tightly secure the spacers that have theplates positioned therebetween. It is believed more important to havethe spacers tighter when the jig is closed than the plates themselvesfor the simple reason that the plates 1 and 2 cannot go anywhere if thespacers 28 and 80 are locked at top and bottom.

When the die has been closed as shown in FIG. 8 the tubes 3 and 4 whichare the same are inserted through the large openings in the front gaugeplate 18 and threaded through the corresponding bells 6 of the drawnholes 5 in the plates 1 and 2 and pass rearwardly to the rear plate 20as shown in FIGS. 3 and 5. The holes in the rear plate 2(l areinsufficient size to receive the tubes but are sufficient to receive theheads 12 of the expanding mandrels 11. When all of the tubes have beenshoved home they pass inwardly beyond the inner face of the forwardmember 18 and are stopped when they abut the inner face of the rear wallmember 20. At this time the mandrels 11 with their trailing heads 12 areinserted in the tubes and they are moved rearwardly through the alignedholes 82 in the wall 20 and interlock in the crosshead 83 on the rearside of the plate 20 as shown in FIG. 9. The leading ends of themandrels 11 are provided with a reduced portion 234 which provides aforward shoulder that is interlocked in the connected and laterallyslidable plates 85 which are actuated by the lever 86 that is shown inFIG. 9. The plates 85 are provided with bayonet-type slots, the largeportion of which is open when the control knob 86 is pulled away fromthe machine. This permits the leading end of each of the mandrels 11 topass through the plates 85 after they have been fully inserted. The knob86 is moved inwardly to engage in the reduced section 84 as shown inFlG. 9 and thereby lock each of the mandrels 11 to the crosshead 33. Atthis time the cylinder 87 as shown in FIG. is energized to pull itspiston rod 88 as shown in FlGS. 5 and 9 rearwardly. The piston rod 88 issecured to the bridge member 90 that is in turn secured to the crosshead83 and when the piston draws the crosshead 83 rearwardly on the track 91each of the mandrels are drawn through the tubes 3 and 4 with theirheads 12 expanding the same as illustrated in FIG. 2 for securelylocking each drawn hole 5 to its respective tube. The force of drawingis applied to the inner surface of the rear wall member and each of thetubes 3 and 4 have the same length and they are precut so that they aresubstantially the same length so when they engage the rear wall theywill protrude equidistant beyond the end plates of the cell when out ofthe jig, as in FIG. 10. As shown in FIG. 9 each of the mandrels 11 aredrawn rearwardly until they pass through the openings 82 which clear thehead 12 of each mandrel.

Thus with this single operation all of the tubes in the cell areexpanded simultaneously when the plates of the cell are clamped in thejig in proper spaced relation. Thus the expansion of the tubes in eachplate of the cell prepositions these plates relative to each other inaccordance with the spacers 28 of the jig. When the mandrels 11 clearthe rear end wall 20, the knob 86 is drawn away from the machine tounlock the leading end of each mandrel from the crosshead 83 and permitthe mandrels to again be returned to the stack at the front of themachine as shown in FIG. 3.

When this has been completed the cylinder 76 is energized to extend thepiston 77 until the whole of the head 65 is raised from its interlockedposition as shown in FIG. 7 at which time the pin 75 is removed and thecounterweight is effective to permit the same to be turned to itsuppermost position as shown in H6. 3.

Since the tubes 3 and 4 clear the inner surface of the front wall byreason of the fact that they are actually within the initial spacers 28and since the other ends of the tubes are against the inner surface ofthe far wall, the elevator may be raised by energizing the cylinder 21to lift the completed cell out of the jig as illustrated in FIG. 10.Here the cell 92 rests on top of the elevator platforms 25 and 26 asshown in FIG. 3 and may be raised free from the jig. Of course, when thecell 92 is raised, the plates may move together in one direction or theother because there is nothing holding them from moving the tubes 3 and4 longitudinally relative to each other.

The cell 92 is then lifted to the carriage 93 which is supported onrollers and is provided with the top crossbars 94, the forward endmembers 95, the rear end members 96 and a platform made of two bottomtransverse members 97 shown in FIGS. 11 and 12. The upper surface of thecrossmembers 97 and the under surface of the crossmembers 94 areprovided with opposed grooves to receive spacer members 98. At least twoof these spacer members may be slid into the grooves at each end and inthe center of the stack. The spacer members 98 have long bifurcatedsections to fit above or below each of the tubes 3 and 4 and they are ofthe proper gauge and thickness which when inserted in the grooves willmaintain the adjacent plates the same distance apart as that of the jigshown in FIG. 3 without distorting the plates or otherwise straining thefastening between the tubes 3 and 4 and their respective drawn holes 5.

After the gauge plates 98 have been positioned the carriage 93 is movedforward between the saws 100 which trim the ends of each of the tubes 3and 4 and the cell 92 is thus held in proper position. This trimmingoperation is merely a trimming operation. Just a small amount of metalis trimmed from each end of the tube so as to properly gauge all of thetubes and after the carriage has passed completely between the saws theends of each of the tubes 3 and 4 at opposite ends have been cut touniform length and provide the same distance between the ends of thetubes and the respective plates at the end of the cell.

The carriage is then drawn rearwardly and the gauge members 98 arewithdrawn to release the cell from the carriage leaving the cellproperly gauged for mounting.

As shown in FIG. 13 each cell has mounted on each end thereof aninsulating end wall panel 101 which is provided with molded marginalside flanges 102 to provide rigidity in these insulating members. Aseries of holes are formed in each insulating member 101 which arealigned with the respective tubes 3 and 4 of the cell 92. The stem ofeach headed rod 103 is sufficiently small to pass through the respectivetubes 3 and 4 and is inserted through the holes in both of theinsulating end panels 101 and their length is such that when the head104 engages its respective insulating end wall panel and its oppositeend projects approximately three-sixteenths of an inch through the otherinsulating end wall panel or sufficient distance to permit the insertionof the speed nut 105 shown in FIG. 1 at the opposite end of the rod 103from the head 104 of each insulated end wall panel. The stems of therods 103 passing through the tubes 3 also pass through a metal conductorstrap 106 before the speed nuts 105 are applied. One end of each ofthese metal conductor straps is provided with a threaded socket 107which is employed as a positive cell conductor connection, and each ofthe negative plates 2 in the stack are grounded. As a precautionarymeasure a second conductor strap 108 is extended from one of the lowerrods passing through one of the tubes 4 connecting the same to the lowermetal bracket 109 that extends across the upper and lower ends of bothinsulating end wall panels and is secured thereto.

The lower and upper metal channels 110 and 111 extend across the lowerand upper ends of the two insulating end wall panels 101 and are securedto the brackets 109 which retain the lower portions of the cell rigid.Each of these metal channels 110 and 111 are provided with opposedchannel flanges 112. The upper and lower channel flanges 112 in thefront of the cell overlap the rectangular frame of the ionizing unit.

The ionizing unit comprises a ground plate with two transverse barmembers 113 and 114 connected vertically by a series of uniformly spacedvertically disposed parallel negative electrodes 115 which are welded tothe upper and lower transverse members 113 and 114 and are ribbed toprovide strength. This provides a rigid reinforcing metal member thatnot only connects the respective lower and upper bracket members 110 and111 but also provides a mechanically rigid structure in the cell itself.

Two insulators 116 are provided in each of the transverse bar members113 and 114 for supporting the charged or positive electrodes which arein the form of wires 117 suspended vertically between or on oppositesides of the vertical negative electrodes 115 and one end of which ishooked to a bus bar not shown at the top and the other end of each wirebeing hooked to an electrical spring 120 the end of which is hooked tothe lower bus bar 121. Both bus bars 121 are mounted on the oppositeends of the spaced insulators 116. The ends of the upper bus bar may beturned downwardly and provided with a threaded opening 122 to receive athreaded rod which may pass through either insulated wall member 101 forthe purpose of applying a separate positive charge to the top bus barand thus to each of the positively charged ionizing wires 117.

The metal conductor straps 106 with their threaded socket 107 representa separate voltage connection for the positively charged plates 1 whichin the cell shown in FIG. 13 represents the second conductor strapadjacent the top or bottom of the insulating end wall panel 101 whereasthe negatively charged plates 2 represent the inner conductor straps orrows of bolt heads 104 of the cell as illustrated in FIG. 13 and areconnected by the conductor strap 108 to at least one metal bracketacross the bottom of the insulated end wall panels 101.

Thus each end of the cell may have its positive plates independentlyconnected. Again each end of the cell may have the positive ionizingwires 117 independently interconnected to the charge of the circuit.This permits the charging and control circuit to be mounted on eitherend of the cell and the mere removal of this unit from the cell entirelydisconnects the same which is necessary in order to remove the cell andprovides a high degree of electrical safety.

The supply circuit shown in FIG. 15 provides an ordinary potentiometerin the primary circuit of a high voltage transformer 131, the secondaryof which has one terminal connected between a bank of solid staterectifiers 132, 133, the anode of one of which is connected to groundand the cathode of the other of which is connected to the ionizer wires117. The other side of the secondary of the transformer is connectedbetween resistor 134, 135, the other end of one resistor 134 of which isconnected to the ionizer wires 117 and has also connected in paralleltherewith a capacitor 136. The other end of the secondary winding isalso directly connected to the positive plates 1. As previously statedthe negative plates 2 and 115 as well as the casing are connected toground. Such a current supply is connected to the orginary line such asllS-l20 volt 60 cycle circuit and there is no connection between theprimary and secondary coils of the high voltage transformer. Thisprovides a very efficient operating circuit for electronic air cleanersof this character.

The opposed channels 129 between the upper and lower channels 110 and111 on the rear side of the cell are arranged to receive a slide,supporting some form of mechanical dust collector that would catch andhold large globules of dirt that would be knocked from the adjacentplates by a partial discharge together with the current of air. Screensof this character are sometimes reusable but more frequently they arethe throw-away type employing some form of plastic as the texture forcatching the dirt that is freed from the cell.

Referring to FIG..14, two strips of material 1' and 2' are fed from tworolls of strip to the single die 123 in the punch press 124. This dualdie punches the positive and negative plates 1 and 2 at the same time.This dual die punches out the holes 13 and predraws the holes in each ofthe plates 1 and 2. This may require a single or two-stage punchingoperation but the only or last stage cuts the plates 1 and 2 from thisstrip. These plates are shown protruding from the die 123 and during thenext stroke of the die they become severed and drop into the upwardlyopen troughs 125 and 126. Since the trough 125 is straight and has asingle sharp slope, the overhanging plate 1 drops onto this straight andsteep chute and thus travels to the pile 127 ahead of plate 2 whichtravels on chute 126 a further distance and is not quite so steep. Thusplate 1 is always ahead of plate 2 and they 'are alternately stackedautomatically in the pile 127 in the tote box 128 which has a bottom andat least a back and one side. In this manner the bottom of each stack isalways plate 1 and the top is plate 2 when the stack is removed tothejig for assembly.

The strip is automatically fed to and through the die until the punchedand severed plates drop on their respective chutes 125 and 126.

The three-phase circuit of FIG. 17 is merely a duplication of the singlephase circuit of FIG. with the secondary of the transformer supplyingpower from each phase of the threephase transformer.

Referring now to FIG. 17, the conductor tube 3 shown is provided with anonround expanded exterior surface which follows the contours of itsnonround expanded bore. In this instance, the expanded spiral or rifledbore was produced by a mandrel having six lead teeth on its head. Themandrel is rotated as it is drawn through the tube thereby producing ahexagon cross section on the outer surface of the tube.

These expanded nonround tube surfaces provide many more advantages overthe straight or round bore conductor tubes because the points of extremeexpansion of the conductor tube outer surface permits greater lateralexpansion extremes of the tube than would be permitted with a smoothbore expansion. In other words, when a smooth rounded mandrel isemployed to expand the conductor tube, the characteristics of the metaltube will not permit the entire outer surface or circumference of thetube to be stretched and expanded to the extreme radial limit of theoutside rifling bulge of the conductor tube 3 illustrated in FIG. 17.However, when the tube is expanded to a nonround shape, the mostprotruding portions of the expanded tube exterior are permitted by thetube of the same characteristics to stretch to an outer radial limitwhich is greater than that permissible when the entire tube is uniformlyexpanded. This therefore permits greater expansion at points about thetube for :more secure interlock of the tube exterior with thefrustoconical portion of a predrawn hole of a respective collector plate1 or 2.

Secondly, the uniform cross section configuration of the tube outerdiameter assures better interlock with the respective predrawn holesthan does a smooth conductor tube outer surface with a smooth predrawnhole interior. Thus the nonround expanded tube configuration of thepresent invention provides a tighter connection with a greater interlockmechanically as well as electrically.

Another important feature of the spiral or rifled configuration inparticular, is that it has been observed that when a smooth headedmandrel is drawn through the conductor tubes to expand the same, thatthe tubes will no longer remain axially straight and will wander or bendin a direction transverse to their axis. The result is that thecolllector plates 1 and 2 are warped by reason of the conductor tubesbending away from and towards each other. This phenomenon particularlyoccurs adjacent the ends of the cell structure. By rifling the bores ofconductor tubes 3 and 4 to expand the same, the tubes remain axiallystraight thereby preventing any warping of the cell plate structureresulting in a unit which is extremely dependable and which will notfail during use by reason of a short occurring between adjacent endcollecting plates.

In FIG. 17, the conductor tube 3 is shown abutting end panel 101 whichis provided with alignment hole which is smaller than the outsidediameter of conductor tube 3 and is axially aligned with the borethereof. It is not necessary that each and every conductor tube have aconnecting bolt 103 passing therethrough as illustrated in FIG. 13. Inorder to prevent the costly use of more of these bolts 103 thanrequired, selected of the tube ends may be positioned and held inalignment with their respective aligning holes in the end panels bymeans of spring positioning lock lugs such as illustrated at M1. Theselock lugs are cylindrically shaped and slightly tapered at their forwardend 142 and are provided with an annular outwardly extending shoulder orlip 143 which engages the outer surface of the insulating panel 101. Thespring lug 141 is open for its entire length as indicated at 144 inorder to provide spring resiliency in the radial direction of thecylindrical shaped lug. The lug is also provided with outwardly strucklocking ears 145 which yield inwardly when the locking lug is initiallyforced into the opening 140 as viewed from the right-hand side of FIG.17 and subsequently spring outwardly to their natural position to engagethe inside surface of end panel 101 to prevent dislodgment of thelocking lug. The tube end is thus maintained and. positioned and alignedrelative to the other conductor tubes of the cell structure and thusconnecting bolts I03 need only be provided for half of the conductortubes as better illustrated in FIG. 18 and 19.

The collection cell structure of FIGS. 18 and 19 is basically the sameas that previously illustrated in FIG. 13 and others with the exceptionof novel features in the end panels and the other panels making up theouter casing or housing for the collector cell.

The ionizing unit is basically the same as that illustrated in FIG. 13.However, the uniformly spaced vertically disposed parallel electrodes115 are made as an integral part of transverse bar members 113 and 1141.Rather than being welded to the latter, the structure is unitarilyconstructed by punching' out a plate or sheet to provide the rearwardlystruck and uniformly spaced parallel ionizing ground electrodes.

A unique feature resides in the end panel 146 which in this instance ismetal rather than an insulating material which is much more costly. Thepanel member 146 is provided with spaced cutouts 147 with insulatingplates 148 attached loosely thereover.

These insulating plates 148 are loosely secured to the metal panelmember 146 by means of rivets 1419 to permit slight movement of the samefor required assembly alignment of their aligning holes 140 with thebores of their respective conductor tubes 3 or 4.

Those conductor tubes 4 which are grounded in this instance, need not beinsulated as conductor tubes 3 are and therefore the ends of conductortubes 4 may directly abut the grounded metal end panel member 146.However, in order to compensate for the depth of the cutouts 147,depressions 150 are provided in the metal end panel member 146 so thatthe tubes of equal length will abut the end panel in the same verticalplane to provide the proper spacing between alternate groups of thecollecting plates.

Referring to the end view of the structure as shown in FIG. 19, it maybe observed that the bottom insulating plate or panel 148 is providedwith a conductor strap 151 on the outside thereof. This conductor strapis electrically connected through the panel to conductor bar 152, asseen in FIG. 18, which is in turn'electrically connected to the ionizingbar member 121 to provide a positive potential on the ionizing wires orconductors 117. Thus, conductor strap 151 permits end electricalconnection of the cell unit to an energy source by a spring electricalcontact or the like.

The same principal is also applied in the employment of conductor strap153 on the outer face of the lower insulating panel 148. This conductorstrap is electrically connected to the lower positive conductor tubes 3such that an outside electrical end connection to an energy source maybe readily made to the cell structure by an electrical spring contact orthe like. These conductive end straps thus eliminate awkward electricalconnections when the unit is installed.

End panel member 146 is provided with side flanges 154 and top andbottom flanges 155 which provide rigidity to the structure and availableconnecting space for securing the end panels to identical top and bottomchannel members 156 and the unitary ionizing electrode structureconsisting of bars 113, 114 and the vertically disposed negativeelectrodes 115. As illustrated, these structures are riveted together bymeans of rivets 157.

Top and bottom channel members 156 have their inturned side flanges 8overlapping the sides of end panel 146 in order to provide opposed topand bottom troughs both on the upstream and downstream side of the unitto receive mechanical filter screens and to add to the rigidity of thestructure.

We claim:

1. An electronic air-cleaning collector cell consisting of a series ofalternate parallel collecting plates providing interleaved groups ofdifferent polarity, a plurality of aligned mounting holes and clearanceholes in each group of collecting plates, conductor tubes in saidmounting holes to support their respective group of collecting plates ofone polarity and spaced from each other and passing through saidclearance holes of alternate groups of collecting plates of differentpolarity, a pair of spaced opposed end panels on opposite sides of andparallel with said alternate series of collecting plates, said endpanelshaving holes matching the location of the bores of said conductor tubesbut smaller than the outside diameters of said conductor tubes, meanscooperating with said conductor tubes and panel holes to abut and securethe inside faces of said end panels against the ends of all of saidconductor tubes to maintain said alternate groups of collecting platesaligned and in equally spaced parallel relation with each other in saidelectronic air-cleaning cell, and insulating means on said end panels toinsulate said conductor tubes of different polarity.

2. The electronic air-cleaning collector cell of claim 1 which alsoincludes a nonround expanded outer surface on said eonductor tubesinterlocked in their reshaped respective collector plate-mounting holes.

3. The electronic air-cleaning collector cell of claim 2 which alsoincludes a bore of nonround configuration in said conductor tubes whichformed said expanded conductor tube surfaces interlocking their reshapedrespective collector platemounting holes.

4. The electronic air-cleaning collector cell of claim 3 which alsoincludes a spiraled bore in said conductor tubes which expanded saidconductor tube surfaces in their interlocked and reshaped respectivecollector plate-mounting holes.

5. The electronic air-cleaning collector cell of claim 2 including anonround polygonal bore as said nonround bore in said conductor tubeswhich formed said expanded conductor tube surfaces in their interlockedand reshaped respective collector plate-mounting holes.

6. The electronic air-cleaning collector cell of claim 1 includingselected of said conductor tubes of matched gauge length.

7. The electronic air-cleaning collector cell of claim 1 wherein all ofsaid conductor tubes supporting said conductor plates are of equallength to space said conductor plates equally from each other.

8. The electronic air-cleaning cleaning collector cell of claim 1including predrawn mounting holes in said interleaved collector plateseach having a frustoconical section extending beyond the plane of itscollecting plate, said expanded exterior surface of each conductor tubehaving changed the shape of said conical section to interlock with saidpredrawn mounting hole to retain said plates in uniform spaced relation.

9. An electronic air-cleaning collector cell including spaced opposedend panels with outward extending parallel flanges, a series ofalternate parallel collecting plates each having aligned clearance andmounting holes, said mounting holes fixed on spaced and expandedconductor tubes of different polarity and of equal length with theirends against the inner faces of said opposed end panels, insulationmeans between said conductor tubes on said end panels carrying thosetubes to receive a charge, and bolt means extending through said endpanels and selected of said conductor tubes to clamp said end panelsagainst said conductor tubes to support said series of collector platesfor the width of said cell.

10. The structure of claim 9 including a unitary ionizing ground plateshaped to form upper and lower parallel bars with uniformly rearwardlystruck equally spaced parallel ionizing electrodes therebetween, spacedinsulators on each bar supporting opposed bus rods above and below theends of said rearwardly struck ionizing electrodes and between which aresuspended ionizing wires substantially centered between said ionizingelectrodes, a flange extending rearwardly from the top and bottommarginal edges of said upper and lower bars of said ionizing groundplate, and the outer ends of said bars of said ionizing ground platesecured to the front flanges of said end panels.

11. An electronic air-cleaning cell including opposed spaced cell endpanels with parallel edge flanges, a series of alternately disposedcollector plates providing groups of different polarity and with spacedclearance and predrawn mounting holes, spaced and expanded conductortubes of equal length with their ends abutting against the inner facesof said end panels, insulation means between said conductor tubes andsaid end panels to insulatingly support said conductor tubes ofdifferent polarity from each other, hole means in said end panelssmaller than the outer diameter of said conductor tubes and aligned withthe bores of said conductor tubes each to receive an aligning means,selected of said panel hole means and conductor tubes receiving boltstems with their heads against the outer face of one panel and boltfastening means against the outer surface of said other panel to securesaid end panels in clamping engagement against the ends of saidconductor tubes to equally space said collecting plates from each otherand support them relative to said parallel flanges, a unitary ionizingground plate having upper and lower parallel bars with rearwardly struckuniformly spaced parallel ionizing electrodes, spaced insulators on eachbar carrying opposed bus rods above and below said ionizing electrodes,ionizing wires suspended between said bus rods and substantiallycentered between said ionizing electrodes to complete the ionizer, andthe opposite ends of said ionizing ground plate bars secured to saidparallel flanges of said panels.

12. The electronic air-cleaning cell of claim 11 which also includes aflange extending rearwardly from the top and bottom marginal edges ofsaid upper and lower bars of said ionizing ground plate to overlie topand bottom parallel flanges on said end panels.

13. The electronic air-cleaning cell of claim 11 which also includes anopposed top and bottom having intumed marginal side flanges extendedbeyond the side flange of said end panels with the intermediate portionof the ends of said top and bottom secured to top and bottom marginalend flanges on said end panels to form opposed troughs on the up anddown stream sides of said cell to receive mechanical filter screens andadd to the rigidity of said cell.

14. The electronic air-cleaning cell of claim ll which also includes endpanels of insulating material with marginal side flanges, top and bottomcross angles secured to each of said end panels to provide top andbottom end flanges.

15. The electronic air-cleaning cell of claim 11 which also includesopposed upper cutouts in said end panels of metal and closed byoverlying attached insulating plates for each upper charge-carryingtube, opposed lower cutouts in said end panels closed by lower attachedinsulating plates to receive the ends of said conductor tubes, saidattached insulated plates loosely attached to said end panels to permitalignment of their aligning conductor tube holes with the bores of saidconductor tubes, and independent depressions in said steel panels forselected grounded tubes to compensate for the cutout to equalize thespacing between said end panel surfaces.

16. The electronic air-cleaning cell of claim 15 which also includes aconductor strap means connecting said charged tubes on the outside ofsaid lower insulating plates for lateral electrical cell connection toan energy source.

17. The electronic air-cleaning cell of claim 16 which also includes aconductor strap on each of said lower insulating plates connected to theadjacent end of said ionizing wire bus rod for lateral electrical endconnection on either end panel side of said cell to an energy source.

18. An electronic air-cleaning cell end panel comprising a metal panelmember having spaced cutouts, insulating plates overlying selected ofsaid cutouts and having at least one aligning hole therethrough, andattachment means loosely securing said insulating plates to said endpanel member to permit alignment of said holes with selected collectingplate conductor tubes, and depressions in said panel members for otherselected collecting plate conductor tubes to compensate for the depth ofsaid cutouts thereby permitting the ends of said tubes to engage saidend panel in the same vertical plane.

2. The electronic air-cleaning collector cell of claim 1 which alsoincludes a nonround expanded outer surface on said conductor tubesinterlocked in their reshaped respective collector plate-mounting holes.3. The electronic air-cleaning collector cell of claim 2 which alsoincludes a bore of nonround configuration in said conductor tubes whichformed said expanded conductor tube surfaces interlocking their reshapedrespective collector plate-mounting holes.
 4. The electronicair-cleaning collector cell of claim 3 which also includes a spiraledbore in said conductor tubes which expanded said conductor tube surfacesin their interlocked and reshaped respective collector plate-mountingholes.
 5. The electronic air-cleaning collector cell of claim 2including a nonround polygonal bore as said nonround bore in saidconductor tubes which formed said expanded conductor tube surfaces intheir interlocked and reshaped respective collector plate-mountingholes.
 6. The electronic air-cleaning collector cell of claim 1including selected of said conductor tubes of matched gauge length. 7.The electronic air-cleaning collector cell of claim 1 wherein all ofsaid conductor tubes supporting said conductor plates are of equallength to space said conductor plates equally from each other.
 8. Theelectronic air-cleaning cleaning collector cell of claim 1 includingpredrawn mounting holes in said interleaved collector plates each havinga frustoconical section extending beyond the plane of its collectingplate, said expanded exterior surface of each conductor tube havingchanged the shape of said conical section to interlock with saidpredrawn mounting hole to retain said plates in uniform spaced relation.9. An electronic air-cleaning collector cell including spaced opposedend panels with outward extending parallel flanges, a series ofalternate parallel collecting plates each having aligned clearance andmounting holes, said mounting holes fixed on spaced and expandedconductor tubes of different polarity and of equal length with theirends against the inner faces of said opposed end panels, insulationmeans between said conductor tubes on said end panels carrying thosetubes to receive a charge, and bolt means extending through said endpanels and selected of said conductor tubes to clamp said end panelsagainst said conductor tubes to support said series of collector platesfor the width of said cell.
 10. The structure of claim 9 including aunitary ionizing ground plate shaped to form upper and lower parallelbars with uniformly rearwardly struck equally spaced parallel ionizingelectrodes therebetween, spaced insulators on each bar supportingopposed bus rods above and below the ends of said rearwardly struckionizing electrodes and between which are suspended ionizing wiressubstantially centered between said ionizing electrodes, a flangeextending rearwardly from the top and bottom marginal edges of saidupper and lower bars of said ionizing ground plate, and the outer endsof said bars of said ionizing ground plate secured to the front flangesof said end panels.
 11. An electronic air-cleaning cell includingopposed spaced cell end panels with parallel edge flanges, a series ofalternately disposed collector plates providing groups of differentpolarity and with spaced clearance and predrawn mounting holes, spacedand expanded conductor tubes of equal length with their ends abuttingagainst the inner faces of said end panels, insulation means betweensaid conductor tubes and said end panels to insulatingly support saidconductor tubes of different polarity from each other, hole means insaid end panels smaller than the outer diameter of said conductor tubesand aligned with the bores of said conductor tubes each to receive analigning means, selected of said panel hole means and conductor tubesreceiving bolt stems with their heads against the ouTer face of onepanel and bolt fastening means against the outer surface of said otherpanel to secure said end panels in clamping engagement against the endsof said conductor tubes to equally space said collecting plates fromeach other and support them relative to said parallel flanges, a unitaryionizing ground plate having upper and lower parallel bars withrearwardly struck uniformly spaced parallel ionizing electrodes, spacedinsulators on each bar carrying opposed bus rods above and below saidionizing electrodes, ionizing wires suspended between said bus rods andsubstantially centered between said ionizing electrodes to complete theionizer, and the opposite ends of said ionizing ground plate barssecured to said parallel flanges of said panels.
 12. The electronicair-cleaning cell of claim 11 which also includes a flange extendingrearwardly from the top and bottom marginal edges of said upper andlower bars of said ionizing ground plate to overlie top and bottomparallel flanges on said end panels.
 13. The electronic air-cleaningcell of claim 11 which also includes an opposed top and bottom havinginturned marginal side flanges extended beyond the side flange of saidend panels with the intermediate portion of the ends of said top andbottom secured to top and bottom marginal end flanges on said end panelsto form opposed troughs on the up and down stream sides of said cell toreceive mechanical filter screens and add to the rigidity of said cell.14. The electronic air-cleaning cell of claim 11 which also includes endpanels of insulating material with marginal side flanges, top and bottomcross angles secured to each of said end panels to provide top andbottom end flanges.
 15. The electronic air-cleaning cell of claim 11which also includes opposed upper cutouts in said end panels of metaland closed by overlying attached insulating plates for each uppercharge-carrying tube, opposed lower cutouts in said end panels closed bylower attached insulating plates to receive the ends of said conductortubes, said attached insulated plates loosely attached to said endpanels to permit alignment of their aligning conductor tube holes withthe bores of said conductor tubes, and independent depressions in saidsteel panels for selected grounded tubes to compensate for the cutout toequalize the spacing between said end panel surfaces.
 16. The electronicair-cleaning cell of claim 15 which also includes a conductor strapmeans connecting said charged tubes on the outside of said lowerinsulating plates for lateral electrical cell connection to an energysource.
 17. The electronic air-cleaning cell of claim 16 which alsoincludes a conductor strap on each of said lower insulating platesconnected to the adjacent end of said ionizing wire bus rod for lateralelectrical end connection on either end panel side of said cell to anenergy source.
 18. An electronic air-cleaning cell end panel comprisinga metal panel member having spaced cutouts, insulating plates overlyingselected of said cutouts and having at least one aligning holetherethrough, and attachment means loosely securing said insulatingplates to said end panel member to permit alignment of said holes withselected collecting plate conductor tubes, and depressions in said panelmembers for other selected collecting plate conductor tubes tocompensate for the depth of said cutouts thereby permitting the ends ofsaid tubes to engage said end panel in the same vertical plane.